Silicon-Based Heat Dissipation Device For Heat-Generating Devices

ABSTRACT

Embodiments of a silicon-based heat dissipation device and a chip module assembly are described. An apparatus may include a silicon-based heat dissipation device, an extended device coupled to the silicon-based heat-dissipation device and heat-generating devices mounted on the silicon-based heat dissipation device. The silicon-based heat dissipation device may include a base portion having a first primary side and a second primary side opposite the first primary side. The silicon-based heat dissipation device may also include a protrusion portion on the first primary side of the base portion and protruding therefrom. The protrusion portion may include multiple fins. The base portion may include a slit opening with a first heat-generating device of the heat-generating devices on a first side of the slit opening and a second heat-generating device of the heat-generating devices on a second side of the slit opening opposite the first side of the slit opening.

CROSS REFERENCE TO RELATED PATENT APPLICATION

This is a continuation-in-part (CIP) of U.S. patent application Ser. No.13/929,791, filed on 28 Jun. 2013 and issued as U.S. Pat. No. 9,159,642on 13 Oct. 2015, which is a non-provisional of U.S. Patent ApplicationNo. 61/807,655, filed 2 Apr. 2013 and entitled “Silicon-Based HeatDissipation Device For Heat-Generating Devices”. The aforementionedapplications are incorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure generally relates to the field of transfer ofthermal energy and, more particularly, removal of thermal energy fromelectrically-driven devices.

BACKGROUND

There are many applications, ranging from consumer electronics totelecommunications and the like, in which electrically-driven devices(e.g., electronic devices such as semiconductor-based integratedcircuits) capable of performing various tasks are packed in closeproximity in a small form factor to serve various needs. Suchelectrically-driven devices may include, for example, driver circuits,microprocessors, graphics processors, memory chips, global positioningsystem (GPS) chips, communications chips, laser diodes includingedge-emitting lasers and vertical-cavity surface-emitting lasers(VCSELs), light-emitting diodes (LEDs), photodiodes, sensors, etc. Manyof such electrically-driven devices inevitably generate thermal energy,or heat, in operation and thus are heat sources during operation as wellas for a period of time after power off. As the number and complexity ofthe functionalities performed by such electrically-driven devicescontinue to increase and as the distance between electrically-drivendevices in the small form factor continues to decrease, heat generatedby such electrically-driven devices, as heat sources, present technicalchallenges that need to be addressed.

For one thing, performance, useful lifespan, or both, of anelectrically-driven device may be significantly impacted if the heatgenerated by the device is not adequately dissipated or otherwiseremoved from the device. Moreover, in many present-day applications,given the close proximity between two or more electrically-drivendevices on the same substrate, e.g., printed circuit board (PCB), aphenomenon of thermal coupling between the two or more devices in closeproximity may occur and result in the heat generated by one of thedevices being transferred to one or more adjacent devices. When thermalcoupling occurs, at least a portion of the heat generated by a firstelectrically-driven devices is transferred to a secondelectrically-driven device in close proximity due to temperaturegradient, such that the temperature of the second electrically-drivendevice rises to a point higher than it would be when no heat istransferred from the first electrically-driven device to the secondelectrically-driven device. More specifically, when thermal couplingoccurs and when no adequate heat transfer mechanism exists, heatgenerated by electrically-driven devices in close proximity maydetrimentally deteriorate the performance and useful lifespan of some orall of the affected devices. As electrically-driven devices generateheat, they are referred to as heat-generating devices hereinafter.

Metal heat sinks or radiators, based on copper or aluminum for example,have been a dominant heat sink choice for electronics or photonicsapplications. As the form factor of electronic components (e.g.,integrated circuits or IC) gets smaller it is impractical to build asmall metal heat sink with a large surface area heat sink. Otherproblems associated with metal heat sinks include, for example,difficulty in precision alignment in mounting laser diode bars, VCSELs,LEDs or chips in laser diode/VCSEL/LED cooling applications, issues withoverall compactness of the package, corrosion of the metallic materialin water-cooled applications, difficulty in manufacturing,high-precision fabrication, electrical isolation, etc. Yet, increasingdemand for higher power density in small form factor motivates theproduction of a compact cooling package with fewer or none of theaforementioned issues. Moreover, conventional packages typically usewire bonding to provide electrical power to the electrically-drivendevice(s) being cooled, but wire bonding may add cost and complexity inmanufacturing and may be prone to defects in addition to occupying spaceunnecessarily.

SUMMARY

Various embodiments disclosed herein pertain to a technique, design,scheme, device and mechanism for isolation of thermal ground formultiple heat-generating devices on a substrate.

In one aspect, an apparatus may include a plurality of heat-generatingdevices, a silicon-based heat dissipation device and an extended devicecoupled to the silicon-based heat-dissipation device. The silicon-basedheat dissipation device may include a base portion having a firstprimary side and a second primary side opposite the first primary side.The silicon-based heat dissipation device may also include a protrusionportion on the first primary side of the base portion and protrudingtherefrom. The protrusion portion may include a plurality of fins. Thesecond primary side of the base portion may be configured to receive theheat-generating devices thereon such that at least a portion of heatgenerated by the heat-generating devices is dissipated to thesilicon-based heat-dissipation device by conduction. The base portionmay include a slit opening with a first heat-generating device of theheat-generating devices on a first side of the slit opening and a secondheat-generating device of the heat-generating devices on a second sideof the slit opening opposite the first side of the slit opening. Theextended device may include an extended layer and one or more spacersdisposed between the extended layer and the silicon-based heatdissipation device.

In some embodiments, the extended layer may include a printed circuitboard (PCB).

In some embodiments, the extended layer may include a silicon-basedlayer.

In some embodiments, the extended layer may include a glass displaylayer.

In some embodiments, an area of the extended layer may be configured todisplay textual information, graphical information, pictorialinformation, video images, or a combination thereof.

In some embodiments, each of the one or more spacers may be disposedbetween a respective corner of the extended layer and a respectivecorner of the silicon-based heat dissipation device to provide a gaptherebetween.

In some embodiments, a thickness of each of the one or more spacers maybe greater than a height of each of the heat-generating devices.

In some embodiments, the apparatus may further include a thermalinterface material disposed between the silicon-based heat dissipationdevice and at least one of the heat-generating devices.

In another aspect, an apparatus may include a plurality ofheat-generating devices, a silicon-based heat dissipation device, and anextended device coupled to the silicon-based heat-dissipation device.The silicon-based heat dissipation device may include anelectrical-connection medium, a base portion having a first primary sideand a second primary side opposite the first primary side, and aprotrusion portion on the first primary side of the base portion andprotruding therefrom. The protrusion portion may include a plurality offins. The second primary side of the base portion may include aplurality of recesses each configured to receive a respective one of theheat-generating devices therein such that at least a portion of heatgenerated by the heat-generating devices is dissipated to thesilicon-based heat-dissipation device by conduction. The second primaryside of the base portion may also include a recessed channel thatconnects the recesses to one another. The electrical-connection mediummay be disposed in the recessed channel and electrically connecting theheat-generating devices to one another. The extended device may includean extended layer.

In some embodiments, a depth of each of the recesses may be greater thana height of each of the heat-generating devices.

In some embodiments, the electrical-connection medium may include a wirelaid in the recessed channel or an electroplated pattern printed on asurface of the recessed channel.

In some embodiments, the extended layer may include a PCB.

In some embodiments, the extended layer may include a silicon-basedlayer.

In some embodiments, the extended layer may include a glass displaylayer.

In some embodiments, an area of the extended layer may be configured todisplay textual information, graphical information, pictorialinformation, video images, or a combination thereof.

In some embodiments, the extended device may further include one or morespacers disposed between the extended layer and the silicon-based heatdissipation device.

In some embodiments, a thickness of each of the one or more spacers maybe greater than a height of each of the heat-generating devices.

In some embodiments, each of the one or more spacers may be disposedbetween a respective corner of the extended layer and a respectivecorner of the silicon-based heat dissipation device to provide a gaptherebetween.

In some embodiments, the apparatus may also include a thermal interfacematerial disposed between the silicon-based heat dissipation device andthe external device.

In some embodiments, the apparatus may further include a thermalinterface material disposed between the silicon-based heat dissipationdevice and at least one of the one or more heat-generating devices.

The proposed techniques are further described below in the detaileddescription. This summary is not intended to identify essential featuresof the claimed subject matter, nor is it intended for use in determiningthe scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of the present disclosure. The drawings illustrate embodiments ofthe disclosure and, together with the description, serve to explain theprinciples of the disclosure. It is appreciable that the drawings arenot necessarily in scale as some components may be shown to be out ofproportion than the size in actual implementation in order to clearlyillustrate the concept of the present disclosure.

FIG. 1 is a partial cross-sectional view of a heat dissipation device inaccordance with an embodiment of the present disclosure.

FIG. 2 is a partial cross-sectional view of a heat dissipation device inaccordance with an embodiment of the present disclosure.

FIG. 3 is a partial cross-sectional view of a heat dissipation device inaccordance with an embodiment of the present disclosure.

FIG. 4 is a perspective view of a heat dissipation device in accordancewith an embodiment of the present disclosure.

FIG. 5 is a partial cross-sectional view of the heat dissipation deviceof FIG. 4.

FIG. 6 is a perspective top view of a device in accordance with anembodiment of the present disclosure.

FIG. 7 is a perspective bottom view of the device of FIG. 6.

FIG. 8 is a side view of the device of FIG. 6.

FIG. 9 is a perspective top view of a device in accordance with anotherembodiment of the present disclosure.

FIG. 10 is a perspective bottom view of the device of FIG. 9.

FIG. 11 is a perspective view of a chip module assembly utilizing heatdissipation devices in accordance with an embodiment of the presentdisclosure.

FIG. 12 is an exploded view of the chip module assembly of FIG. 11.

FIG. 13 is a perspective view of a device in accordance with yet anotherembodiment of the present disclosure.

FIG. 14 is an enlarged cross-sectional view of the device of FIG. 13.

FIG. 15 is a perspective view of a chip module assembly utilizing heatdissipation devices in accordance with another embodiment of the presentdisclosure.

FIG. 16 is an exploded view of the chip module assembly of FIG. 15.

FIG. 17 is an enlarged cross-sectional view of the chip module assemblyof FIG. 15.

FIG. 18 is an enlarged cross-sectional view of a chip module assembly inaccordance with yet another embodiment of the present disclosure.

FIG. 19 is an exploded view of a chip module assembly utilizing heatdissipation devices in accordance with an embodiment of the presentdisclosure.

FIG. 20 is a first perspective view of the chip module assembly of FIG.19.

FIG. 21 is a second perspective view of the chip module assembly of FIG.19.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Overview

A compact heat sink or radiator built with silicon-based materialprovide a compact and highly efficient heat sink for all electronicsapplications such as driver circuits, microprocessors, graphicsprocessors, memory chips, GPS chips, communications chips, laser diodesincluding edge-emitting lasers and VCSELs, LEDs, photodiodes, sensors,etc. One advantage of a silicon-based heat sink or radiator is that itcan have a surface area more than ten times that of a typicalmetal-based heat sink or radiator which may be fabricated by extrusion,stamping or machining process. Besides, the surface quality of thesilicon fins of a silicon-based heat sink or radiator can reach anoptically polished quality surpassing the surface quality ofconventional metal-based heat sinks and radiators. A silicon-based heatsink or radiator does not corrode or become tarnished in atmosphere dueto elements of the environment. In contrast, metal-based heat sinks andradiators tend to foul and/or corrode over time. The aforementionedadvantages enhance the reliability and thermal dissipation efficiency ofsilicon-based heat sinks and radiators.

Illustrative Implementations

Each of FIGS. 1-3 respectively illustrates a partial cross-sectionalview of a silicon-based heat dissipation device in accordance with anembodiment of the present disclosure. FIG. 4 illustrates a silicon-basedheat dissipation device 101 in accordance with an embodiment of thepresent disclosure. FIG. 5 illustrates dimensions associated with thesilicon-based heat dissipation device of FIG. 4. The followingdescription refers to FIGS. 1-5.

Each of FIGS. 1-3 illustrates a respective embodiment of across-sectional view of a fin structure of multiple straight fins of asilicon-based heat dissipation device 101. Due to efficient thermalperformance and compact structure of the silicon-based heat dissipationdevice 101, a surface area at least ten times that of a typicalmetal-based heat sink or radiator to interact with air or air-solcooling can be achieved.

FIG. 1 shows an embodiment of a first design 51 in which sidewalls ofthe fins are parallel or substantially parallel to one another. Forinstance, as shown in FIG. 1, the width of the cross section of each ofthe fins in design 51 may remain substantially the same throughout theheight of the fin, with a dimension d near the bottom portion of the finand with the dimension d near the top or tip of the fin. Also, thebottom of the fin structure where a fin is connected to its immediatelyadjacent fin(s) may be flat or substantially flat.

FIG. 2 shows an embodiment of a second design 52 in which sidewalls ofthe fins are tapered. For instance, as shown in FIG. 2, the width of thecross section of each of the fins in design 52 may gradually decrease ina linear or non-linear fashion, with a dimension D near the bottomportion of the fin and with a dimension d near the top or tip of thefin, where D is greater than d. Also, the bottom of the fin structurewhere a fin is connected to its immediately adjacent fin(s) may be flator substantially flat. In embodiments in which the width of the crosssection of each of the fins gradually decreases in a linear fashion(shown in FIG. 2), a contour of the cross section of a fin may be astraight line. In embodiments in which the width of the cross section ofeach of the fins gradually decreases in a non-linear fashion (notshown), a contour of the cross section of a fin may be curved, or havingat least a portion curved and at least another portion straight (e.g.,partially curved and partially straight).

FIG. 3 shows an embodiment of a first design 53 in which sidewalls ofthe fins are parallel or substantially parallel to one another. Forinstance, as shown in FIG. 3, the width of the cross section of each ofthe fins in design 53 may remain substantially the same throughout theheight of the fin, with a dimension d near the bottom portion of the finand with the dimension d near the top or tip of the fin. Different fromdesign 51, in design 53 the bottom of the fin structure where a fin isconnected to its immediately adjacent fin(s) may grooved with across-sectional shape that resembles a V-notch shape.

The silicon-based heat dissipation device 101 shown in FIG. 4 can befabricated from a piece of single-crystal silicon by etching variousstructural shapes as shown in FIGS. 1-3. As shown in FIG. 4, thesilicon-based heat dissipation device 101 has a base portion 2 and aprotrusion portion 1. The base portion 2 has a first primary side (e.g.,the side that faces up in FIG. 4) and a second primary side (e.g., theside that faces down in FIG. 4) opposite the first primary side. Theprotrusion portion 1 of the silicon-based heat dissipation device 101 ison the first primary side of the base portion 2 and protrudes therefrom.In the example shown in FIG. 4, the protrusion portion 1 includesmultiple straight fins. The multiple straight fins of the protrusionportion 1 may be spaced apart from each other by an equidistant spacing11. Additionally or alternatively, the protrusion portion 1 may includepin fins and/or flared fins. In one embodiment, the silicon-based heatdissipation device 101 may be made from a single-crystal silicon waferwhere multiple grooves are etched onto one side of the silicon wafer byetching, e.g., chemical etching, to form the multiple straight fins ofthe protrusion portion 1. In some embodiments, the multiple straightfins of the protrusion portion 1 may be formed to adopt design 51 ofFIG. 1. In some embodiments, the multiple straight fins of theprotrusion portion 1 may be formed to adopt design 52 of FIG. 2. In someembodiments, the multiple straight fins of the protrusion portion 1 maybe formed to adopt design 53 of FIG. 3. In some embodiments, one portionof the multiple straight fins of the protrusion portion 1 may be formedto adopt one of design 51, design 52 or design 53, while another portionof the multiple straight fins of the protrusion portion 1 may be formedto adopt the other of design 51, design 52 or design 53.

As shown in FIG. 5, there are several dimensions associated with thesilicon-based heat dissipation device 101. T1 denotes a thickness of thebase portion 2 that is measured across the base portion 2 in a directionparallel to the first primary side of the base portion 2. T2 denotes aheight of the protrusion portion 1, or the fins of the protrusionportion 1, that is measured from the first primary side of the baseportion 2 in a direction perpendicular to the first primary side of thebase portion 2. T3 denotes a width of the spacing 11 between every twoadjacent fins of the protrusion portion 1. T4 denotes a thickness ofeach of the fins of the protrusion portion 1, measured across arespective one of the fins in a direction parallel to the first primaryside of the base portion 2.

In one embodiment, the ratio T2:T4 is a large number in order toincrease the surface area of the silicon-based heat dissipation device101 in a small footprint of silicon base. In order to achieve a highconvective cooling in the silicon-based heat dissipation device 101, theratio of T2:T4 is greater than 5:1. Similarly, the ratio T2:T1 isgreater than 5:1. Moreover, in one embodiment, T3 is greater than orequal to T4. These dimensions and ratios provide an optimum performanceof the silicon-based heat dissipation device 101. For example, if eachof the dimensions T3 and T4 is 100 microns with T2 being 500 microns andT1 being 100 microns, then the silicon-based heat dissipation device 101would have a large amount of surface area in a compact form factor.However, air flow through the spacing 11 between every two adjacent finsof the protrusion portion 1 may be restricted due to small gap, T3 toineffectively remove all heat from silicon fin. To maximize thermalconvection by air flow through the spacing 11 between every two adjacentfins of the protrusion portion 1, in various implementations thedimension T3 and air speed can be increased to achieve quick removal ofheat from the fins of the silicon-based heat dissipation device 101.

FIGS. 6-8 illustrate a device 100 in accordance with an embodiment ofthe present disclosure. The following description refers to FIGS. 6-8.

FIG. 6 shows the device 100 which is a monolithic structure of IC chipor Silicon-On-Insulator (SOI) combined with the silicon-based heatdissipation device 101. Typically integrated circuits are developed orlaid-down on a primary side of a silicon wafer, and then the backside ofthe silicon wafer opposite the primary side is lapped to make a thinsilicon IC chip. In one embodiment, the silicon-based heat dissipationdevice 101 is built or attached to the backside of the IC or SOI chip toincrease the heat dissipation by increasing the surface area of theexisting backside of the IC or SOI structure. The silicon-based heatdissipation device 101 built on the backside of the IC or SOI chipprovides more than ten times (10×) of surface area to dissipate heatfrom the integrated circuits by convection or forced air, compared toconventional metal-based heat sinks or radiators.

As shown in FIGS. 7 and 8, each of heat-generating devices 21-25 isembedded in or physically coupled, mounted or otherwise attached to thesecond primary side of the base portion 2, which is preferably flat andsmooth to facilitate maximum contact, and thus thermal conduction, withthe heat-generating devices 21-25. Each of heat-generating devices 23and 25 may be an embedded or doped integrated circuit while each ofheat-generating devices 21, 22 and 24 may be a driver chip,microprocessor, graphics processor, memory chip, GPS chip,communications chip, laser diode (edge-emitting or VCSEL), LED,photodiode, sensor or the like. Regardless what the case may be, each ofheat-generating devices 21-25 generates heat when powered on for whichheat needs to be removed to prolong the operational life and enhance theperformance of the heat-generating devices 21-25. One of ordinary skillin the art would appreciate that, although multiple heat-generatingdevices are shown in FIGS. 7 and 8, in various embodiments the number ofheat-generating devices may be more or less depending on the actualimplementation. Although a fixed number of heat-generating devices isshown in FIG. 7, in various embodiments according to the presentdisclosure there may be a different number of heat-generating devices.

FIGS. 9 and 10 illustrate a device 200 in accordance with anotherembodiment of the present disclosure. The following description refersto FIGS. 9 and 10.

The device 200 and the device 100 are similar in many ways. In theinterest of brevity, detailed description of differences between thedevice 200 and the device 100 is provided herein while similaritytherebetween is not repeated. As shown in FIGS. 9 and 10, the device 200includes a silicon-based heat dissipation device 102 that has a baseportion 6 and a protrusion portion 5. The base portion 6 has a firstprimary side and a second primary side opposite the first primary side.The protrusion portion 5 is on the first primary side of the baseportion 6 and protrudes therefrom. The protrusion portion 5 may includemultiple straight fins similar to those of the protrusion portion 1 ofthe silicon-based heat dissipation device 101. For example, thesilicon-based heat dissipation device 102 may be made from asingle-crystal silicon wafer where multiple grooves are etched onto oneside of the silicon wafer by etching, e.g., chemical etching, to formthe multiple straight fins of the protrusion portion 5. In someembodiments, the multiple straight fins of the protrusion portion 5 maybe formed to adopt design 51 of FIG. 1. In some embodiments, themultiple straight fins of the protrusion portion 5 may be formed toadopt design 52 of FIG. 2. In some embodiments, the multiple straightfins of the protrusion portion 5 may be formed to adopt design 53 ofFIG. 3. In some embodiments, one portion of the multiple straight finsof the protrusion portion 5 may be formed to adopt one of design 51,design 52 or design 53, while another portion of the multiple straightfins of the protrusion portion 5 may be formed to adopt the other ofdesign 51, design 52 or design 53.

The silicon-based heat dissipation device 102 includes a slit opening 12on the base portion 6 that fluidly or communicatively connects the firstprimary side and the second primary side of base portion 6. That is, theslit opening 12 traverses the thickness of base portion 6. The slitopening 12 cuts off, or severs, a direct-line thermal coupling path viaconduction through the base portion 6 between a first heat-generatingdevice on one side of the slit opening 12 and a second heat-generatingdevice on the other side of the slit opening 12. As shown in FIG. 9, atleast one fin of the multiple fins of protrusion portion 5 may bedissected by at least one portion of the slit opening 12 into twoseparate fins. In one embodiment, the slit opening 12 may include anL-shaped slit opening as shown in FIGS. 9 and 10. Alternatively, theslit opening 12 may include a straight line, a non-straight line, acurved line or a zigzag line, depending on the actual implementation. Inother embodiments, instead of a slit opening, the base portion 6 mayinclude a trench or groove on either its first primary side or secondprimary side. Whether a slit opening or a groove or trench, such designwould minimize thermal coupling by conduction between two or moreheat-generating devices that are disposed on the heat dissipation device102.

In the example shown in FIG. 10, each of heat-generating devices 26-29is embedded in or physically coupled, mounted or otherwise attached tothe second primary side of the base portion 6, which is preferably flatand smooth to facilitate maximum contact, and thus thermal conduction,with the heat-generating devices 26-29. As shown in FIG. 10, theheat-generating device 26 is on one side of the L-shaped slit opening 12while the heat-generating devices 27, 28 and 29 are on the other side ofthe L-shaped slit opening 12. The slit opening 12 provides the functionof severing a direct-line thermal coupling path (i.e., thermalconduction path) through the base portion 6 between the heat-generatingdevice 26 and each of the heat-generating devices 27, 28 and 29. In thisway, the absolute temperature of each of the heat-generating device 27,28 and 29 can be more effectively lowered since they would not be heatedby heat from the heat-generating device 26. This arrangement may besuitable, for example, when the heat-generating device 26 (e.g., amicroprocessor) generates more heat than each of the heat-generatingdevices 27, 28 and 29 during operation. In one embodiment, thesilicon-based heat dissipation device 102 may be fabricated on thebackside of an IC or SOI chip. Although a fixed number ofheat-generating devices is shown in FIG. 10, in various embodimentsaccording to the present disclosure there may be a different number ofheat-generating devices.

FIGS. 11 and 12 illustrate a chip module assembly 103 in accordance withan embodiment of the present disclosure. The following descriptionrefers to FIGS. 11 and 12.

Chip module assembly 103 may include an assembly of a silicon-based heatdissipation device 102″ and an extended device 104 bonded, affixed orotherwise coupled to each other. For instance, silicon-based heatdissipation device 102″ and extended device 104 may be bonded togetherwith a thermal interface material disposed therebetween to facilitatethermal transfer from one to the other, and vice versa. Similar tosilicon-based heat dissipation device 102, silicon-based heatdissipation device 102″ may include a base portion 6 and a protrusionportion 5. The base portion 6 has a first primary side and a secondprimary side opposite the first primary side. The protrusion portion 5is on the first primary side of the base portion 6 and protrudestherefrom. The protrusion portion 5 may include multiple straight finssimilar to those of the protrusion portion 1 of the silicon-based heatdissipation device 101. For example, the silicon-based heat dissipationdevice 102 may be made from a single-crystal silicon wafer wheremultiple grooves are etched onto one side of the silicon wafer byetching, e.g., chemical etching, to form the multiple straight fins ofthe protrusion portion 5. In some embodiments, the multiple straightfins of the protrusion portion 5 may be formed to adopt design 51 ofFIG. 1. In some embodiments, the multiple straight fins of theprotrusion portion 5 may be formed to adopt design 52 of FIG. 2. In someembodiments, the multiple straight fins of the protrusion portion 5 maybe formed to adopt design 53 of FIG. 3. In some embodiments, one portionof the multiple straight fins of the protrusion portion 5 may be formedto adopt one of design 51, design 52 or design 53, while another portionof the multiple straight fins of the protrusion portion 5 may be formedto adopt the other of design 51, design 52 or design 53.

In addition, silicon-based heat dissipation device 102″ may include aconnector 55 which may be disposed on the same side/surface ofsilicon-based heat dissipation device 102″ on which heat-generatingdevices 26-29 are disposed. In some embodiments, a thermal interfacematerial may be sandwiched between silicon-based heat dissipation device102″ and at least one of heat-generating devices 26-29 to aid thermaltransfer of heat from the respective heat-generating device(s) tosilicon-based heat dissipation device 102″. Additionally, silicon-basedheat dissipation device 102″ may include an electrical-connection medium54 that provides electrical connection between two or more ofheat-generating devices 26-29 and connector 55. Electrical-connectionmedium 54 may be, for example and not limited to, one or more wires,ribbon cables, electroplated patterns, or a combination thereof.Although a fixed number of heat-generating devices is shown in FIG. 12,in various embodiments according to the present disclosure there may bea different number of heat-generating devices.

Similar to silicon-based heat dissipation device 102, silicon-based heatdissipation device 102″ may also include a slit opening 12 on the baseportion 6 that cuts off, or severs, a direct-line thermal coupling pathvia conduction through the base portion 6 between a firstheat-generating device on one side of the slit opening 12 and a secondheat-generating device on the other side of the slit opening 12. In oneembodiment, the slit opening 12 may include an L-shaped slit opening asshown in FIG. 12. Alternatively, the slit opening 12 may include astraight line, a non-straight line, a curved line or a zigzag line,depending on the actual implementation. In other embodiments, instead ofa slit opening, the base portion 6 may include a trench or groove oneither its first primary side or second primary side. Whether a slitopening or a groove or trench, such design would minimize thermalcoupling by conduction between two or more heat-generating devices thatare disposed on the heat dissipation device 102″.

In the example shown in FIG. 12, each of heat-generating devices 26-29is embedded in or physically coupled, mounted or otherwise attached tothe second primary side of the base portion 6, which is preferably flatand smooth to facilitate maximum contact, and thus thermal conduction,with the heat-generating devices 26-29. As shown in FIG. 12, theheat-generating device 26 is on one side of the L-shaped slit opening 12while the heat-generating devices 27, 28 and 29 are on the other side ofthe L-shaped slit opening 12. The slit opening 12 provides the functionof severing a direct-line thermal coupling path (i.e., thermalconduction path) through the base portion 6 between the heat-generatingdevice 26 and each of the heat-generating devices 27, 28 and 29. In thisway, the absolute temperature of each of the heat-generating device 27,28 and 29 can be more effectively lowered since they would not be heatedby heat from the heat-generating device 26. This arrangement may besuitable, for example, when the heat-generating device 26 (e.g., amicroprocessor) generates more heat than each of the heat-generatingdevices 27, 28 and 29 during operation. In one embodiment, thesilicon-based heat dissipation device 102″ may be fabricated on thebackside of an IC or SOI chip.

Extended device 104 may be a single-layer device or a multi-layerdevice. Extended device 104 may include, for example and not limited to,a circuit board (e.g., a PCB), a silicon-based layer, a siliconsubstrate or a glass display layer. In some embodiments, extended device104 may be a silicon-based PCB with a display layer configured todisplay textual information, graphical information, pictorialinformation, video images, or a combination thereof. In someembodiments, extended device 104 may be a silicon substrate that, whenbonded together with silicon-based heat dissipation device 102″,sandwich or otherwise embed heat-generating devices 26-29 therebetween.

In the example shown in FIGS. 11 and 12, extended device 104 may includean extended layer 61 with an area 62 thereon. Extended layer 61 may be acircuit board (e.g., a PCB), a silicon-based layer or a siliconsubstrate configured for one or more IC chips to attach thereto, or aglass display layer (e.g., glass display panel), and can be connected tosilicon-based heat dissipation device 102″. In some embodiments,extended layer 61 may include a combination of two or more of a circuitboard, a silicon-based layer and a glass display layer. Area 62 may be adesignated area on extended layer 61. In some embodiments, area 62 maybe configured to display textual information, graphical information,pictorial information, video images, or a combination thereof. In someembodiments, area 62 may be configured for mounting of one or moreelectrical devices, components and/or chips thereon.

Extended device 104 may also include one or more spacers 65 disposedbetween extended device 104 and silicon-based heat dissipation device102″ to provide a gap therebetween. For instance, each of the one ormore spacers 65 may be disposed between a respective corner of extendedlayer 61 and a respective corner of silicon-based heat dissipationdevice 102″. The thickness of each of the one or more spacers 65 may begreater than a height of each of heat-generating devices 26-29 andconnector 55. This arrangement allows a proper gap to be formed betweenextended device 104 and silicon-based heat dissipation device 102″.Extended device 104 may further include a connector 66 that is disposedbetween extended device 104 and silicon-based heat dissipation device102″. Connector 66 may be configured to provide one or more electricalconnections between silicon-based heat dissipation device 102″ andextended device 104. For instance, area 62 or one or more electricaldevices/components mounted on area 62 may be powered by electricityreceived from silicon-based heat dissipation device 102″ via connector66.

Thus, chip module assembly 103 may be an assembly of extended device 104and silicon-based heat dissipation device 102″ with a slit or groove(e.g., L-shaped slit 12). Silicon-based heat dissipation device 102″ maybe packaged tightly with electrical/electronic components such asheat-generating devices 26-29 and still be thermal-managed by protrusion5 of silicon-based heat dissipation device 102″. Extended device 104 andsilicon-based heat dissipation device 102″ may be electrically connectedto each other via connector 55 and connector 66. Accordingly, chipmodule assembly 103 may be a compact and high-powerelectrical/electronic apparatus (e.g., a mobile phone, a smartphone, atable computer, a wearable device or similar electronic equipment) or asub-system thereof.

FIGS. 13 and 14 illustrate a silicon-based heat dissipation device 201in accordance with yet another embodiment of the present disclosure. Thefollowing description refers to FIGS. 13 and 14.

Silicon-based heat dissipation device 201 may be a variation ofsilicon-based heat dissipation device 102″. Similar to silicon-basedheat dissipation device 102″, silicon-based heat dissipation device 201may include a base portion 6 and a protrusion portion 5. The baseportion 6 has a first primary side and a second primary side oppositethe first primary side. The protrusion portion 5 is on the first primaryside of the base portion 6 and protrudes therefrom. The protrusionportion 5 may include multiple straight fins similar to those of theprotrusion portion 1 of the silicon-based heat dissipation device 101.For example, the silicon-based heat dissipation device 102 may be madefrom a single-crystal silicon wafer where multiple grooves are etchedonto one side of the silicon wafer by etching, e.g., chemical etching,to form the multiple straight fins of the protrusion portion 5. In someembodiments, the multiple straight fins of the protrusion portion 5 maybe formed to adopt design 51 of FIG. 1. In some embodiments, themultiple straight fins of the protrusion portion 5 may be formed toadopt design 52 of FIG. 2. In some embodiments, the multiple straightfins of the protrusion portion 5 may be formed to adopt design 53 ofFIG. 3. In some embodiments, one portion of the multiple straight finsof the protrusion portion 5 may be formed to adopt one of design 51,design 52 or design 53, while another portion of the multiple straightfins of the protrusion portion 5 may be formed to adopt the other ofdesign 51, design 52 or design 53.

On the second primary side of the base portion 6, silicon-based heatdissipation device 201 may include one or more recesses such as recesses71, 72, 73, 74 and 75. This may be done by, for example, etching thesecond primary side of silicon-based heat dissipation device 102 to formthe one or more recesses 71-75. Each of the one or more recesses 71-75may be configured, shaped, sized or otherwise adapted to accommodate orreceive a respective heat-generating device or electrical/electroniccomponent. For instance, recess 71 may be configured to accommodate orreceive heat-generating device 27 to be mounted therein, recess 72 maybe configured to accommodate or receive heat-generating device 28 to bemounted therein, recess 73 may be configured to accommodate or receiveheat-generating device 29 to be mounted therein, recess 74 may beconfigured to accommodate or receive heat-generating device 26 to bemounted therein, and recess 75 may be configured to accommodate orreceive connector 55 to be mounted therein. In some embodiments, athermal interface material may be sandwiched between silicon-based heatdissipation device 201 and at least one of heat-generating devices 26-29and connector 55 to aid thermal transfer of heat from the respectiveheat-generating device(s) and/or electrical/electronic component tosilicon-based heat dissipation device 201.

Preferably, a depth of at least one or each of the one or more recesses71-75 may be greater or deeper than a height of the respectiveheat-generating devices and electrical/electronic component to beaccommodated or otherwise received therein. In some other embodiments,the depth of at least one or each of the one or more recesses 71-75 maybe substantially equal to the height of each of the respectiveheat-generating devices and electrical/electronic component to beaccommodated or otherwise received therein. Alternatively, the depth ofat least one or each of the one or more recesses 71-75 may be less orshallower than the height of each of the respective heat-generatingdevices and electrical/electronic component to be accommodated orotherwise received therein.

Silicon-based heat dissipation device 201 may also include a groove orrecessed channel 56 that connects the one or more recesses 71-75 to oneanother. This may be done by, for example, etching the second primaryside of silicon-based heat dissipation device 102 to form the recessedchannel 56. Accordingly, the one or more spacers 65 may be unnecessaryalthough the one or more spacers 65 may still be used. For instance, inembodiments in which silicon-based heat dissipation device 201 is usedin place of silicon-based heat dissipation device 102″ in chip moduleassembly 103, the use of one or more spacers 65 may be unnecessary andthe chip module assembly 103 may be more compact. Recessed channel 56may be configured, shaped, sized or otherwise adapted to accommodate orreceive one or more wires, ribbon cables, electroplated patterns, or acombination thereof to electrically connect at least some of theheat-generating devices 26-29 and connector 55 when mounted,accommodated or otherwise received in the recesses 71-75.

In addition, as with silicon-based heat dissipation device 102″,silicon-based heat dissipation device 201 may include a connector 55which may be disposed on the same side/surface of silicon-based heatdissipation device 201 on which heat-generating devices 26-29 aredisposed. Additionally, silicon-based heat dissipation device 201 mayinclude an electrical-connection medium 54 that provides electricalconnection between two or more of heat-generating devices 26-29 andconnector 55. Electrical-connection medium 54 may be, for example andnot limited to, one or more wires, ribbon cables, electroplatedpatterns, or a combination thereof. In the example shown in FIGS. 13 and14, electrical-connection medium 54, which may be a wire laid orprovided in recessed channel 56 or an electroplated pattern printed ordeposited on a surface (e.g., a bottom surface) of recessed channel 56.

Similar to silicon-based heat dissipation device 102″, silicon-basedheat dissipation device 201 may also include a slit opening 12 on thebase portion 6 that cuts off, or severs, a direct-line thermal couplingpath via conduction through the base portion 6 between a firstheat-generating device on one side of the slit opening 12 and a secondheat-generating device on the other side of the slit opening 12. In oneembodiment, the slit opening 12 may include an L-shaped slit opening asshown in FIG. 12. Alternatively, the slit opening 12 may include astraight line, a non-straight line, a curved line or a zigzag line,depending on the actual implementation. In other embodiments, instead ofa slit opening, the base portion 6 may include a trench or groove oneither its first primary side or second primary side. Whether a slitopening or a groove or trench, such design would minimize thermalcoupling by conduction between two or more heat-generating devices thatare disposed on the heat dissipation device 201.

FIGS. 15-17 illustrate a chip module assembly 203 utilizing heatdissipation devices in accordance with another embodiment of the presentdisclosure. The following description refers to FIGS. 15-17.

Chip module assembly 203 may include an assembly of silicon-based heatdissipation device 201 and extended device 104 bonded, affixed orotherwise coupled to each other. For instance, silicon-based heatdissipation device 201 and extended device 104 may be bonded togetherwith a thermal interface material disposed therebetween to facilitatethermal transfer from one to the other, and vice versa. As eachcomponent module assembly 203 has been described above, in the interestof brevity a detailed description of chip module assembly 203 is notprovided so as to avoid redundancy. Although a fixed number ofheat-generating devices is shown in FIG. 16, in various embodimentsaccording to the present disclosure there may be a different number ofheat-generating devices.

FIG. 18 illustrates a chip module assembly 303 in accordance with yetanother embodiment of the present disclosure. The following descriptionrefers to FIG. 18.

Chip module assembly 203 may include an assembly of silicon-based heatdissipation device 201 and an extended device 204 bonded, affixed orotherwise coupled to each other. For instance, silicon-based heatdissipation device 201 and extended device 204 may be bonded togetherwith a thermal interface material disposed therebetween to facilitatethermal transfer from one to the other, and vice versa. Extended device204 may differ from extended device 104 in that extended device 204 doesnot include any spacer (e.g., one or more spacers 65). Other aspects andfeatures of extended device 204 may be similar or identical to those ofextended device 104. Accordingly, in the interest of brevity a detaileddescription of chip module assembly 303 is not provided so as to avoidredundancy.

In view of the above, a compact, thin and tightly electronic apparatussuch as chip module assemblies 203 and 303 may be provided due to theone or more recesses 71-75 on the second primary side of silicon-basedheat dissipation device 201. That is, the one or more recesses 71-75accommodate or otherwise receive heat-generating devices 26-29 andconnector 55 therein to minimize or prevent the heat-generating devices26-29 and connector 55 from protruding out of the surface of the secondprimary side of silicon-based heat dissipation device 201. This designallows the overall thickness of chip module assemblies 203 and 303 to bereduced as the height of heat-generating devices 26-29 and connector 55would not contribute to the thickness of chip module assemblies 203 and303. This feature optimizes thermal management of chip module assemblies203 and 303 while allowing chip module assemblies 203 and 303 to becompactly packaged. Each of chip module assembly 203 and chip moduleassembly 303 may be a compact and high-power electrical/electronicapparatus (e.g., a mobile phone, a smartphone, a table computer, awearable device or similar electronic equipment) or a sub-systemthereof.

FIGS. 19-21 illustrate an example application of heat dissipationdevices of the present disclosure. In particular, FIGS. 19-21 illustratean example chip cooling application in which a chip module assembly 5001is equipped with a number of heat dissipation devices 101 and/or 102 inaccordance with an embodiment of the present disclosure. The descriptionbelow refers to FIGS. 19-21.

Chip module assembly 5001 may include a chip module 901 and a primaryheat dissipation module. Chip module 901 may include a board 750 (e.g.,a printed circuit board or PCB), a number of memory chips 701 and aserial presence detect (SPD) chip 702. In the example shown in FIGS.19-21, chip module 901 has twenty (20) memory chips 701 with ten memorychips 701 disposed on one side of board 750 and the other ten memorychips 701 disposed on the other side of board 750. The SPD chip 702 isdisposed one side of board 750, e.g., between five of the ten memorychips 701 on that side as shown in FIG. 19. Memory chips 701 mayinclude, for example, SRAM (static random access memory), DRAM (dynamicrandom access memory), EEPROM (electrically erasable programmableread-only memory), flash memory, or any semiconductor memory devicepresently available or developed in the future. Those of ordinary skillin the art would appreciate that, although certain number of memorychips 701 are shown in the example illustrated in FIGS. 19-21, thenumber of memory chips 701 may vary in other embodiments.

The primary heat dissipation module may include silicon-based heatdissipation devices 401 a, 401 b, 401 c, 401 d, 402 a, 402 b, 402 c, 402d and 403. Each of the silicon-based heat dissipation devices 401 a, 401b, 401 c, 401 d, 402 a, 402 b, 402 c, 402 d and 403 may be similar tosilicon-based heat dissipation device 101 or 102 as described above.Thus, in the interest of brevity, detailed description of silicon-basedheat dissipation devices 401 a, 401 b, 401 c, 401 d, 402 a, 402 b, 402c, 402 d and 403 is not provided to avoid redundancy. Those of ordinaryskill in the art would appreciate that, although certain number ofsilicon-based heat dissipation devices are shown in the exampleillustrated in FIGS. 19-21, the number of silicon-based heat dissipationdevices may vary in other embodiments.

Each of the silicon-based heat dissipation devices 401 a, 401 b, 401 c,401 d, 402 a, 402 b, 402 c and 402 d may correspond to one or more ofthe memory chips 701, while the silicon-based heat dissipation device403 may correspond to the SPD chip 702. That is, each of thesilicon-based heat dissipation devices 401 a, 401 b, 401 c, 401 d, 402a, 402 b, 402 c and 402 d may be disposed on or physically coupled,bonded, adhered, mounted or otherwise attached to one or more of thememory chips 701. In the example illustrated in FIGS. 19-21, each ofsilicon-based heat dissipation devices 401 a, 401 b, 401 c and 401 dcorresponds to two of the memory chips 701 and is disposed on orphysically coupled, bonded, adhered, mounted or otherwise attached totwo of the memory chips 701. Likewise, each of silicon-based heatdissipation devices 402 a, 402 b, 402 c and 402 d corresponds to threeof the memory chips 701 and is disposed on or physically coupled,bonded, adhered, mounted or otherwise attached to three of the memorychips 701. As shown in FIGS. 19-21, silicon-based heat dissipationdevice 403 corresponds to the SPD chip 702 and is disposed on orphysically coupled, bonded, adhered, mounted or otherwise attached tothe SPD chip 702. This is because, as the SPD chip 702 tends to producemore heat than a single one of the memory chips 701, the SPD chip 702 iscooled by its own silicon-based heat dissipation device 403 which isseparate from, and thus thermally decoupled from, the othersilicon-based heat dissipation devices 401 a, 401 b, 401 c, 401 d, 402a, 402 b, 402 c and 402 d.

As each of the silicon-based heat dissipation devices 401 a, 401 b, 401c, 401 d, 402 a, 402 b, 402 c and 402 d is disposed on or physicallycoupled, bonded, adhered, mounted or otherwise attached to more than oneof the memory chips 701, in one embodiment, at least one of thesilicon-based heat dissipation devices 401 a, 401 b, 401 c, 401 d, 402a, 402 b, 402 c and 402 d may be similar to the silicon-based heatdissipation device 102 and include one or more slit openings. Forexample, when the respective silicon-based heat dissipation devicecorresponds to two of the memory chips 701, there may be one slitopening that serves to thermally decouple one half of the respectivesilicon-based heat dissipation device which corresponds to one of thetwo memory chips 701 and the other half of the respective silicon-basedheat dissipation device which corresponds to the other one of the twomemory chips 701. Similarly, when the respective silicon-based heatdissipation device corresponds to three of the memory chips 701, theremay be two slit openings that serve to thermally decouple the threesections of the respective silicon-based heat dissipation device whereeach of the three sections of the respective silicon-based heatdissipation device corresponds to one of the three memory chips 701.

In one embodiment, at least one of the silicon-based heat dissipationdevices 401 a, 401 b, 401 c, 401 d, 402 a, 402 b, 402 c, 402 d and 403is solder bonded onto the molding compound of the respective memorychip(s) 701 or SPD chip 702. Alternatively, at least one of thesilicon-based heat dissipation devices 401 a, 401 b, 401 c, 401 d, 402a, 402 b, 402 c, 402 d and 403 is adhered to the respective memorychip(s) 701 or SPD chip 702 by thermally-conductive epoxy.

In other embodiments, the primary heat dissipation module may includemore or fewer silicon-based heat dissipation devices than thatillustrated in FIGS. 19-21. For example, each of the memory chips 701may correspond to a respective one of the silicon-based heat dissipationdevices. In other words, in one embodiment, each of the silicon-basedheat dissipation devices would be disposed on or physically coupled,bonded, adhered, mounted or otherwise attached to a respective one ofthe memory chips 701. Alternatively, one silicon-based heat dissipationdevice may be provided on each side of board 750 such that the chips ona given side of board 750 are in contact with and thus cooled by thesame silicon-based heat dissipation device.

As each of the silicon-based heat dissipation devices 401 a, 401 b, 401c, 401 d, 402 a, 402 b, 402 c, 402 d and 403 is similar to theabove-described silicon-based heat dissipation device 101 or 102, thebase portion of each of the silicon-based heat dissipation devices 401a, 401 b, 401 c, 401 d, 402 a, 402 b, 402 c, 402 d and 403 is disposedon or physically coupled, bonded, adhered, mounted or otherwise attachedto the respective one or more memory chips 701 or the SPD chip 702. Theprotrusion portion of each of the silicon-based heat dissipation devices401 a, 401 b, 401 c, 401 d, 402 a, 402 b, 402 c, 402 d and 403 isexposed to the ambience. Each of the silicon-based heat dissipationdevices 401 a, 401 b, 401 c, 401 d, 402 a, 402 b, 402 c, 402 d and 403is oriented such that the straight fins of the protrusion portion arealigned in the same direction.

For example, as shown in FIGS. 19-21, the straight fins of theprotrusion portion of each of the silicon-based heat dissipation devices401 a, 401 b, 401 c, 401 d, 402 a, 402 b, 402 c, 402 d and 403 isaligned with the longitudinal axis of the board 750 that traverses theboard 750 from one distal end to the opposite distal end of the board750. This allows a relatively smooth air flow to flow through thestraight fins when, for example, one or more fans are provided on onedistal end of the board 750 to provide the air flow. The relativelysmooth air flow results in a laminar flow, as opposed to a turbulentflow, and thereby maximizes heat transfer or dissipation via convectionfrom the silicon-based heat dissipation devices 401 a, 401 b, 401 c, 401d, 402 a, 402 b, 402 c, 402 d and 403 to the air flow.

Chip module assembly 5001 may additionally include a secondary heatdissipation module. The secondary heat dissipation module may includeeither or both of a first frame 301 and a second frame 302. Each of thefirst and second frames 301 and 302 is disposed on a respective side ofthe board 750 over the primary heat dissipation module. For example, asshown in FIGS. 19-21, the first frame 301 is disposed on a first primaryside of the board 750 over the silicon-based heat dissipation devices401 a, 401 b, 402 a, 402 b and 403 and ten of the twenty memory chips701 as well as the SPD chip 702. Correspondingly, as shown in FIGS.19-21, the second frame 302 is disposed on a second primary side of theboard 750 (that is opposite the first primary side of the board 750)over the silicon-based heat dissipation devices 401 c, 401 d, 402 c and402 d and the remaining ten of the twenty memory chips 701. If the chipmodule assembly 5001 has memory chips on one but not both sides of theboard 750, then the secondary heat dissipation module would include onebut not both of the first and second frames 301 and 302.

Each of the first and second frames 301 and 302 may be made of ametallic material or a plastic material. For example, at least one ofthe first and second frames 301 and 302 may be made of aluminum or zinc.Each of the first and second frames 301 and 302 may be disposed on orphysically coupled, bonded, mounted or otherwise attached to the board750 by mechanical means (e.g., screws) or by any other suitable means.As the first and second frames 301 and 302 are similar or identical toone another, the following description of the first frame 301 equallyapplies to the second frame 302.

The first frame 301 may include a louver 303 and posts 304, 305, 306,307, 308, 309 and 310 that protrude from the same side of the frame 301.The louver 303 may include one or more angled surfaces such that thelouver 303 may function as an air flow defector to direct air flowtoward the fins of the silicon-based heat dissipation devices 401 a, 401b, 402 a, 402 b and 403.

Posts 304, 305, 306, 307, 308, 309 and 310 are strategically located onthe first frame 301 such that, when the first frame 301 is disposed onor otherwise mounted to the board 750, posts 307, 308, 309 and 310function as heat-sinking posts around the four corners on the firstprimary side of the board 750 while posts 304, 305 and 306 function asheat-sinking posts around and near the SPD chip 702. In other words, atleast part of the heat generated by memory chips 701 and SPD chip 702can be transferred to the first and second frames 301 and 302 byconduction through the board 750.

An additional function of each of the first and second frames 301 and302 is to provide protection of the fins of the silicon-based heatdissipation devices 401 a, 401 b, 401 c, 401 d, 402 a, 402 b, 402 c, 402d and 403 from damage caused by direct impact/contact with an externalobject.

The design of the primary heat dissipation module and the secondary heatdissipation module provides dual heat-transfer paths to dissipate heatfrom the chip module 901. The primary heat dissipation module (i.e., thesilicon-based heat dissipation devices 401 a, 401 b, 401 c, 401 d, 402a, 402 b, 402 c, 402 d and 403) is in direct contact with the memorychips 701 and SPD chip 702 and thus provides one heat-transfer path todissipate heat from the chip module 901. The secondary heat dissipationmodule (i.e., the first and second frames 301 and 302) is in directcontact with the board 750 and thus provides another heat-transfer pathto dissipate heat from the chip module 901. The primary heat dissipationmodule and the secondary heat dissipation module, however, are not indirection contact with one another and, therefore, are thermallyisolated from one another.

Those of ordinary skill in the art would appreciate that, although theexample illustrated in FIGS. 19-21 involves heat dissipation for memorychips of a memory chip module, embodiments and techniques of the noveland non-obvious design of the present disclosure may as well be appliedto other applications in which the heat-generating devices are notmemory chips. For instance, instead of memory chips, a design similar tothat illustrated in FIGS. 19-21 may be used to cool a chip set thatincludes a microprocessor functioning as a central processing unit (CPU)and one or more other chips such as a graphics processor, one or morememory chips, a network communication chip and/or a wirelesscommunication chip.

In summary, in one aspect of the present disclosure, a device mayinclude a silicon-based heat dissipation device. The silicon-based heatdissipation device may include a base portion and a protrusion portion.The base portion may have a first primary side and a second primary sideopposite the first primary side. The protrusion portion may be on thefirst primary side of the base portion and may protrude therefrom. Thesecond primary side of the base portion may be configured to have one ormore heat-generating devices embedded therein or physically coupledthereto such that at least a portion of heat generated by the one ormore heat-generating devices is dissipated to the silicon-based heatdissipation device by conduction.

In at least one embodiment, the base portion may include a slit openingthat communicatively connects the first primary side and the secondprimary side of the base portion.

In at least one embodiment, when each of more than one heat-generatingdevices is embedded in or physically coupled to the base portion, atleast a first heat-generating device of the more than oneheat-generating devices may be on a first side of the slit opening andat least a second heat-generating device of the more than oneheat-generating devices may be on a second side of the slit openingopposite the first side of the slit opening such that the slit openingsevers a direct-line thermal coupling path via conduction through thebase portion between the first and the second heat-generating devices.

In at least one embodiment, the slit opening may include an L-shapedslit opening.

In at least one embodiment, the protrusion portion of the silicon-basedheat dissipation device may include a plurality of fins.

In at least one embodiment, the plurality of fins may include aplurality of straight fins.

In at least one embodiment, a ratio of a height of the fins, measuredfrom the first primary side of the base portion in a directionperpendicular to the first primary side, to a thickness of each of thefins, measured across a respective one of the fins in a directionparallel to the first primary side of the base portion, may be greaterthan 5:1.

In at least one embodiment, a ratio of a height of the fins, measuredfrom the first primary side of the base portion in a directionperpendicular to the first primary side, to a thickness of the baseportion, measured across the base portion in a direction parallel to thefirst primary side of the base portion, may be greater than 5:1.

In at least one embodiment, a spacing between every two fins of thefins, measured between respective two fins of the fins in a directionparallel to the first primary side of the base portion, may be greaterthan or equal to a thickness of each of the fins, measured across arespective one of the fins in the direction parallel to the firstprimary side of the base portion.

In at least one embodiment, the plurality of fins may include aplurality of pin fins.

In at least one embodiment, the plurality of fins may include aplurality of flared fins.

In at least one embodiment, the device may further include one or moreintegrated circuits embedded in the second primary side of the baseportion or one or more electrically-driven devices physically coupled tothe second primary side of the base portion.

In at least one embodiment, the device may further include one or moreintegrated circuits embedded in the second primary side of the baseportion or one or more electrically-driven devices physically coupled tothe second primary side of the base portion. At least a first one of theone or more integrated circuits or the one or more electrically-drivendevices may be on a first side of the slit opening. At least a secondone of the one or more integrated circuits or the one or moreelectrically-driven devices may be on a second side of the slit openingopposite the first side of the slit opening. The slit opening may severa direct-line thermal coupling path via conduction through the baseportion between the first one of the one or more integrated circuits orthe one or more electrically-driven devices and the second one of theone or more integrated circuits or the one or more electrically-drivendevices.

In at least one embodiment, the silicon-based heat dissipation devicemay be made of single-crystal silicon.

In another aspect, a chip module assembly may include a chip module anda primary heat dissipation module. The chip module may include a boardand at least one heat-generating device. The board may include a firstprimary side and a second primary side opposite the first primary side.The at least one heat-generating device may be disposed on the firstprimary side of the board. The primary heat dissipation module mayinclude at least one silicon-based heat dissipation device disposed onthe at least one heat-generating device.

In at least one embodiment, the at least one silicon-based heatdissipation device may be made of single-crystal silicon.

In at least one embodiment, the at least one silicon-based heatdissipation device may include a base portion and a protrusion portion.The base portion may include a first primary side and a second primaryside opposite the first primary side. The protrusion portion may be onthe first primary side of the base portion and protruding therefrom. Thesecond primary side of the base portion may be in physical contact withthe at least one heat-generating device such that at least a portion ofheat generated by the at least one heat-generating device is dissipatedto the silicon-based heat dissipation device by conduction.

In at least one embodiment, the base portion may include a slit openingthat communicatively connects the first primary side and the secondprimary side of the base portion.

In at least one embodiment, the at least one heat-generating device mayinclude a first heat-generating device and a second heat-generatingdevice. The first heat-generating device may be on a first side of theslit opening and the second heat-generating device may be on a secondside of the slit opening opposite the first side of the slit openingsuch that the slit opening severs a direct-line thermal coupling pathvia conduction through the base portion between the first and the secondheat-generating devices.

In at least one embodiment, the slit opening may be an L-shaped slitopening.

In at least one embodiment, the protrusion portion of the silicon-basedheat dissipation device may include a plurality of fins.

In at least one embodiment, the plurality of fins may include aplurality of pin fins.

In at least one embodiment, the plurality of fins may include aplurality of flared fins.

In at least one embodiment, the plurality of fins may include aplurality of straight fins.

In at least one embodiment, a ratio of a height of the fins, measuredfrom the first primary side of the base portion in a directionperpendicular to the first primary side, to a thickness of each of thefins, measured across a respective one of the fins in a directionparallel to the first primary side of the base portion, may be greaterthan 5:1.

In at least one embodiment, a ratio of a height of the fins, measuredfrom the first primary side of the base portion in a directionperpendicular to the first primary side, to a thickness of the baseportion, measured across the base portion in a direction parallel to thefirst primary side of the base portion, may be greater than 5:1.

In at least one embodiment, a spacing between every two fins of thefins, measured between respective two fins of the fins in a directionparallel to the first primary side of the base portion, may be greaterthan or equal to a thickness of each of the fins, measured across arespective one of the fins in the direction parallel to the firstprimary side of the base portion.

In at least one embodiment, the at least one heat-generating device mayinclude a plurality of heat-generating devices, and the at least onesilicon-based heat dissipation device may include a plurality ofsilicon-based heat dissipation devices each of which disposed on one ormore of the heat-generating devices.

In at least one embodiment, a first portion of the heat-generatingdevices may be disposed on the first primary side of the board and asecond portion of the heat-generating devices may be disposed on thesecond primary side of the board. At least a first one of thesilicon-based heat dissipation devices may be disposed on one or more ofthe heat-generating devices disposed on the first primary side of theboard and at least a second one of the silicon-based heat dissipationdevices may be disposed on one or more of the heat-generating devicesdisposed on the second primary side of the board.

In at least one embodiment, the heat-generating devices may includememory chips.

In at least one embodiment, the chip module assembly may further includea secondary heat dissipation module. The secondary heat dissipationmodule may include a first frame disposed on the first primary side ofthe board of the chip module. The first frame may include a louver and aplurality of posts. The louver may include at least an angled surfacethat directs an air flow toward the at least one silicon-based heatdissipation device. The first frame may be in physical contact with theboard through the plurality of posts.

In at least one embodiment, the primary heat dissipation module and thesecondary heat dissipation module may not be in physical contact withone another.

In at least one embodiment, the first frame may be made of a metallicmaterial.

In at least one embodiment, the secondary heat dissipation module mayfurther include a second frame disposed on the second primary side ofthe board of the chip module. The second frame may include a louver anda plurality of posts through which the second frame is in physicalcontact with the second primary side of the board. The louver mayinclude at least an angled surface.

Additional and Alternative Implementation Notes

The above-described embodiments pertain to a technique, design, scheme,device and mechanism for isolation of thermal ground for multipleheat-generating devices on a substrate. Although the embodiments havebeen described in language specific to certain applications, it is to beunderstood that the appended claims are not necessarily limited to thespecific features or applications described herein. Rather, the specificfeatures and applications are disclosed as example forms of implementingsuch techniques.

In the above description of example implementations, for purposes ofexplanation, specific numbers, materials configurations, and otherdetails are set forth in order to better explain the invention, asclaimed. However, it will be apparent to one skilled in the art that theclaimed invention may be practiced using different details than theexample ones described herein. In other instances, well-known featuresare omitted or simplified to clarify the description of the exampleimplementations.

The described embodiments are intended to be primarily examples. Thedescribed embodiments are not meant to limit the scope of the appendedclaims. Rather, the claimed invention might also be embodied andimplemented in other ways, in conjunction with other present or futuretechnologies.

Moreover, the word “example” is used herein to mean serving as anexample, instance, or illustration. Any aspect or design describedherein as “example” is not necessarily to be construed as preferred oradvantageous over other aspects or designs. Rather, use of the wordexample is intended to present concepts and techniques in a concretefashion. The term “techniques,” for instance, may refer to one or moredevices, apparatuses, systems, methods, articles of manufacture, and/orcomputer-readable instructions as indicated by the context describedherein.

As used in this application, the term “or” is intended to mean aninclusive “or” rather than an exclusive “or.” That is, unless specifiedotherwise or clear from context, “X employs A or B” is intended to meanany of the natural inclusive permutations. That is, if X employs A; Xemploys B; or X employs both A and B, then “X employs A or B” issatisfied under any of the foregoing instances. In addition, thearticles “a” and “an” as used in this application and the appendedclaims should generally be construed to mean “one or more,” unlessspecified otherwise or clear from context to be directed to a singularform.

What is claimed is:
 1. An apparatus, comprising: a plurality ofheat-generating devices; a silicon-based heat dissipation devicecomprising: a base portion having a first primary side and a secondprimary side opposite the first primary side; and a protrusion portionon the first primary side of the base portion and protruding therefrom,the protrusion portion comprising a plurality of fins, wherein: thesecond primary side of the base portion is configured to receive theheat-generating devices thereon such that at least a portion of heatgenerated by the heat-generating devices is dissipated to thesilicon-based heat-dissipation device by conduction, and the baseportion comprises a slit opening with a first heat-generating device ofthe heat-generating devices on a first side of the slit opening and asecond heat-generating device of the heat-generating devices on a secondside of the slit opening opposite the first side of the slit opening;and an extended device coupled to the silicon-based heat-dissipationdevice, the extended device comprising: an extended layer; and one ormore spacers disposed between the extended layer and the silicon-basedheat dissipation device.
 2. The apparatus of claim 1, wherein theextended layer comprises a printed circuit board (PCB).
 3. The apparatusof claim 1, wherein the extended layer comprises a silicon-based layer.4. The apparatus of claim 1, wherein the extended layer comprises aglass display layer.
 5. The apparatus of claim 4, wherein an area of theextended layer is configured to display textual information, graphicalinformation, pictorial information, video images, or a combinationthereof.
 6. The apparatus of claim 1, wherein each of the one or morespacers is disposed between a respective corner of the extended layerand a respective corner of the silicon-based heat dissipation device toprovide a gap therebetween.
 7. The apparatus of claim 1, wherein athickness of each of the one or more spacers is greater than a height ofeach of the heat-generating devices.
 8. The apparatus of claim 1,further comprising: a thermal interface material disposed between thesilicon-based heat dissipation device and at least one of theheat-generating devices.
 9. An apparatus, comprising: a plurality ofheat-generating devices; a silicon-based heat dissipation devicecomprising: an electrical-connection medium; a base portion having afirst primary side and a second primary side opposite the first primaryside; and a protrusion portion on the first primary side of the baseportion and protruding therefrom, the protrusion portion comprising aplurality of fins, wherein: the second primary side of the base portioncomprises a plurality of recesses each configured to receive arespective one of the heat-generating devices therein such that at leasta portion of heat generated by the heat-generating devices is dissipatedto the silicon-based heat-dissipation device by conduction, the secondprimary side of the base portion further comprises a recessed channelthat connects the recesses to one another, the electrical-connectionmedium is disposed in the recessed channel and electrically connectingthe heat-generating devices to one another; and an extended devicecoupled to the silicon-based heat-dissipation device, the extendeddevice comprising an extended layer.
 10. The apparatus of claim 9,wherein a depth of each of the recesses is greater than a height of eachof the heat-generating devices.
 11. The apparatus of claim 9, whereinthe electrical-connection medium comprises a wire laid in the recessedchannel or an electroplated pattern printed on a surface of the recessedchannel.
 12. The apparatus of claim 9, wherein the extended layercomprises a printed circuit board (PCB).
 13. The apparatus of claim 9,wherein the extended layer comprises a silicon-based layer.
 14. Theapparatus of claim 9, wherein the extended layer comprises a glassdisplay layer.
 15. The apparatus of claim 14, wherein an area of theextended layer is configured to display textual information, graphicalinformation, pictorial information, video images, or a combinationthereof.
 16. The apparatus of claim 9, wherein the extended devicefurther comprises one or more spacers disposed between the extendedlayer and the silicon-based heat dissipation device.
 17. The apparatusof claim 16, wherein a thickness of each of the one or more spacers isgreater than a height of each of the heat-generating devices.
 18. Theapparatus of claim 16, wherein each of the one or more spacers isdisposed between a respective corner of the extended layer and arespective corner of the silicon-based heat dissipation device toprovide a gap therebetween.
 19. The apparatus of claim 9, furthercomprising: a thermal interface material disposed between thesilicon-based heat dissipation device and the external device.
 20. Theapparatus of claim 9, further comprising: a thermal interface materialdisposed between the silicon-based heat dissipation device and at leastone of the one or more heat-generating devices.